The instant invention relates to loading docks and more particularly to an inflatable dock seal for enclosing the area between a loading dock opening in a building wall and a truck stationed at the loading dock opening during an unloading or loading operation.
It has been found that the inflatable dock seals, such as the one disclosed in the applicant's prior U.S. Pat. No. 3,994,103, can be effectively utilized for enclosing the areas between the bodies of trucks positioned at loading dock openings in building walls and the adjacent building walls. An inflatable dock seal of this type generally comprises a plurality of elongated tubular inflatable sections which are securable to a building wall adjacent a loading dock opening and a blower mechanism for inflating and maintaining the tubular members in expanded dispositions during loading and unloading operations. It has been found that because dock seals of this type are operative for yieldably engaging the surfaces of truck bodies they can be utilized for enclosing the areas between building walls and the bodies of trucks despite minor variations in the sizes, surface configurations and positions of truck bodies relative to loading dock openings. Accordingly, it has generally been found that dock seals of this type can be effectively utilized for enclosing the areas between the bodies of individual trucks stationed at loading dock openings and the adjacent building walls so that controlled environments within buildings associated with loading dock openings are not disrupted during truck loading and unloading operations.
While dock seals of the above described type have generally been found to be effective for sealing the open areas between the bodies of trucks stationed at loading dock openings in building walls and the adjacent building walls, it has frequently been found that when dock seals are not in use they hang loosely from the surfaces of building walls so that they are unsightly and prone to flapping loosely in the wind. In this regard, while some of the previously available dock seals have included externally mounted counterweight-type retracting mechanisms for retracting the inflatable portions thereof when they are not in use, the previously available counterweight retracting mechanisms have generally also been found to be unsatisfactory. Specifically, they have been found to be highly prone to malfunctioning when they are exposed to sever weather conditions, such as snow, sleet, or freezing rain.
In addition to the above, many of the previously available dock seals have often been found to be incapable of effectively compensating for other than minor variations in the sizes of truck bodies and/or for accommodating for other than minor misalignments in the positions of trucks located at loading dock openings. This is because the previously available dock seals have generally either been adapted to extend directly outwardly from the walls of buildings around loading dock openings, directly inwardly into loading dock openings or directly outwardly from the walls around loading dock openings and then directly inwardly into the openings making them incapable of compensating for significant variations in the lateral positions of the vertical surfaces of truck bodies stationed at loading docks.
The instant invention provides an effective dock seal which overcomes many of the disadvantages of the previously available inflatable dock seals. Specifically, the instant invention provides an inflatable dock seal which includes a plurality of inflatable portions and an improved resilient retracting mechanism for retracting the inflatable portions when the seal is not in use. More specifically, the dock seal of the instant invention includes a pair of opposite side seal sections which are securable to a building wall adjacent opposite side extremities of a loading dock opening and a top seal section which is securable to the building wall adjacent the top extremity of the loading dock opening so that the top seal section extends between the side seal sections. Each of the top and side seal sections includes an inflatable portion which is inflatable to an expanded disposition and retractable to a collapsed disposition and the seal further includes resilient constant force spring means for resiliently retracting at least a portion of the inflatable portions of the side seal sections and the top seal section.
In one embodiment of the dock seal, the spring means comprises a pair of resilient side recoil band assemblies and a resilient top recoil band assembly which are mounted within the inflatable portions of the side seal sections and the top seal section, respectively, and operative for retracting the side seal sections and the top seal section, respectively. In this embodiment the inflatable portions of the side seal sections are preferably unsupported at the upper ends thereof and they are adapted to be mounted on a building wall so that they extend angularly outwardly from the building wall around a loading dock opening and inwardly and together toward the opening when they are in the inflated dispositions thereof. In this embodiment the top seal section preferably includes a support platform which is securable to the wall of a building so that it extends outwardly therefrom and an inflatable portion on the support platform which is downwardly expandable in outwardly spaced relation to the building wall.
In a second embodiment of the seal of the instant invention the retracting means comprises a resilient recoil band assembly for retracting the inflatable portion of the top seal section and a pair of resilient cord retracting mechanisms for retracting the inflatable portions of the side seal sections. The cord retracting mechanisms preferably include elongated resiliently extendable cords having at-rest lengths which are at least approximately half of the height of the side seal sections and mounted within the inflatable portions of the side seal sections. In this embodiment the top seal section and the side seal sections are preferably integrally connected and the side seal sections are preferably adapted so that they extend angularly outwardly from a building wall around a loading dock opening and inwardly and together toward the opening when they are in the inflated dispositions thereof and the top seal section is preferably adapted so that it extends angularly outwardly and downwardly when it is in the inflated disposition thereof.
It has been found that the dock seal of the instant invention can be effectively utilized for enclosing the open area between the wall of a building wall surrounding a loading dock opening and the body of a truck stationed at the loading dock opening. Specifically, it has been found that because the side seal sections of the seal of the instant invention are preferably adapted so that they extend angularly outwardly from a building wall and inwardly and together toward an adjacent loading dock opening, they can more effectively accommodate variations in the sizes and positions of trucks stationed at the loading dock opening. Further, because the seal includes constant force spring retracting means for resiliently retracting at least some of the inflatable portions of the seal sections, the retracting means can be effectively utilized for automatically retracting the inflatable portions without interfering with the ability of the inflating means to inflate the seal to a fully expanded disposition. Further, because the retracting means for the various sections of the seal are located within their respective inflatable portions, the retracting means is fully protected against the elements and hence not prone to failure.
Accordingly, it is a primary object of the instant invention to provide an inflatable dock seal which includes an improved retracting mechanism.
Another object of the instant invention is to provide an inflatable dock seal which includes a resilient constant force spring retracting mechanism.
An even further object of the instant invention is to provide an inflatable dock seal which is adapted to effectively accommodate minor variations in the dimensions and positions of the bodies of trucks stationed at a loading dock.
An even still further object of the instant invention is to provide an improved dock seal comprising inflatable side seal sections which are securable to a building wall around a loading dock opening and constructed so that they extend angularly outwardly from the building wall and inwardly and together toward the opening for engaging the side surfaces of the bodies of trucks stationed at the loading dock opening.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with accompanying illustrative drawings.